Improvement in envelopes



M. J. DUFFEE.

- Envelope.

No.-200 ,442. Patented Feb. 19,1878.

ATTORNEYS.

N. PETERS. PHOTO-UTHOGRAFHEH, WASHINGTONv D C.

UNITED STATES PATENT OFFICE.

MANLY J. DUFFEE, OF MOBILE, ALABAMA, ASSIGNOR TO HIMSELF AND JOHN W.MILLER, OF SAME PLACE.

IMPROVEMENT IN ENVELOPES.

Specification forming part of Letters Patent No. 200,442, dated February19, 1878; application filed October 16, 1877.

The object of this invention is to produce an envelope that cannot beopened after it is once sealed and be reclosed and sealed again withoutbeing torn or so much injured thereby as to exhibit evidence of suchopening.

The invention consists of an improved article of manufacture, to Wit: anenvelope in which the edges of the flaps are subdivided in the mannerhereinafter described.

In the drawings, Figure 1 is an open envelope embodying my invention.Fig. 2 is the same closed. Fig. 3 is a modified form of the envelopeshown in Fig. 1, also open; Fig. 4, the same as Fig. 3 closed.

Similar letters of reference indicate corresponding parts. My inventionis applicable to all envelopes that are sealed by the adherence ofoverlapping and underlapping edges of the paper or other material ofwhich they are composed.

In the envelope shown in the drawing, as in those in ordinary use, theback of the envelope consists of two end flaps, A, and a lower flap,also marked A, the lapping edges of which are joined by themanufacturer, and of a fourth or upper flap, B, which serves to closeand seal the envelope. In my improved envelope the lapping edges of theflaps A and B are subdivided into several parts, as shown in thedrawing, in such a manner that nine overlapping and nine underlappingedges are formed, as indicated by numerals 1 to 9, or

any other convenient number of such edges may be produced by similarsubdivisions.

The said edges so produced alternately overlap and underlap, orinterlock, as shown in the drawings. Mucilage or other similar adhesivesubstance is applied alternately to the outer or inner face of theflaps, as required.

D indicates where the mncilage is applied on the outer face, and C whereapplied to the inner face, of the flaps in the present example.

In the ordinary envelope the mucilage is all applied to the inner edgesof the flaps A and B, and the security of the envelope depends on theadherence of two overlapping edges with the respective underlappingedges or parts-0n tl e line a b 0. With such said ordinary constructionthe envelope may be opened Without difficulty by holding'the edge offlap B over a jet of steam to slightly moisten the muoilage, andinserting a common pen-holder under said edge and moving it carefullyalong the line a b 0,- but with the subdivisions 'described a pen-holdercould not be inserted or moved along between the adhering edges withouttearing or otherwise injuring the paper or material of the envelope.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- An envelope the edges of whose flaps A B MANLY J.DUFFEE.

Witnesses RICHARD B. OWEN, WM. Z. MOORE.

